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Good news: Consuming just 100 fewer calories each day is enough to avert that weight gain.

If you're finding this out a little too late—and you want to actually lose some of that weight—you have to downsize by 500 calories a day. But you don't have to slash them all from your plate.

"You can eat 250 calories less and then burn 250 by walking for 30 to 45 minutes. Over a week, that will produce about a pound of weight loss," says Holly Wyatt, MD, a clinical researcher at the Center for Human Nutrition in Denver. You won't see dramatic changes immediately, but small tweaks like these will pay off over time.

According to a study at the University of North Carolina, the average hamburger is 23 percent larger today than it was in 1977. Choose a pasta dish and salad or soup from the appetizer column, instead.

and eat less during the rest of the meal, says a study from Pennsylvania State University. When salads were topped with low-fat mozzarella and low-calorie Italian dressing instead of high-fat alternatives, women ate 10 percent fewer calories over the course of the day.

When your cell phone rings, slip on your walking shoes and stroll the halls at work or hoof it outside. If you did this for 10 minutes every workday at a moderate 3 mph pace, you’d burn about 1,000 calories a month and lose 3 pounds a year.

Insufficient shut-eye appears to increase production of the stress hormone cortisol, which regulates appetite. High levels seem to worsen bingeing and hunger; moreover, too little sleep could keep your body from burning carbohydrates, which translates to more stored body fat.

The high-protein, low-carb approach may help keep you from losing muscle along with fat, according to a study published in The Journal of Nutrition. According to study author Donald K. Layman, PhD, of the University of Illinois, the amino acid leucine—found in beef, dairy, poultry, fish, and eggs—may help preserve muscle tissue.

A piece of cheese or a cup of milk or yogurt can rev up your metabolism, a University of Tennessee study found. People who cut 500 calories a day from their diets while eating yogurt three times a day lost 13 pounds over 12 weeks, more weight and more body fat than a control group who only cut calories.

How did 346 people in small-town Washington State lose an average of 17 pounds each in 3 months? With regular exercise, balanced eating, and an apple with every meal. The typical apple has 5 grams of fiber, which makes you feel fuller.

The opinions expressed are solely those of the author and do not necessarily reflect the views of Comcast.

Slimming TipsThe most basic way to lose weight is to slash calories. That’s Diet 101. But how many do you really have to cut or burn to see results? It’s simple: You can drop a pound a week by trimming 500 calories each day.